相关论文: Constraining gluon PDFs with quarkonium production

We calculate the NLO corrections for the gluon fragmentation functions to a heavy quark-antiquark pair in ${^{1}\hspace{-0.6mm}S_{0}^{[1]}}$ or ${^{1}\hspace{-0.6mm}S_{0}^{[8]}}$ state within NRQCD factorization. We use integration-by-parts…

We present the first study of coherent exclusive quarkonium ($J/\psi$, $\Upsilon$) photoproduction in ultraperipheral nucleus-nucleus collisions (UPCs) at the LHC in the framework of collinear factorization and next-to-leading order (NLO)…

Gluon fragmentation represents the dominant source of high energy prompt quarkonia at hadron colliders. Fragmentation approximations break down, however, when a quarkonium's transverse momentum becomes comparable to its mass. In this paper,…

The near threshold photo or electroproduction of heavy vector quarkonium off the proton is studied in quantum chromodynamics. Similar to the high-energy limit, the production amplitude can be factorized in terms of gluonic Generalized…

We perform the first simultaneous global QCD analysis of spin-averaged and spin-dependent parton distribution functions (PDFs), including single jet production data from unpolarized and polarized hadron collisions. We critically assess the…

The near-threshold photo- and electroproduction of heavy vector quarkonia off the proton provides direct access to its gluonic structure. In particular, the cross section for $J/\Psi$ photoproduction near threshold is governed by the…

We discuss the potential to constrain the small-$x$ PDFs using the exclusive production of heavy vector mesons. The calculation of $J/\psi$ and $\Upsilon$ photoproduction at NLO in collinear factorisation is described. The different…

The perturbative instability of NLO collinear factorisation (CF) computations of $p_T$-integrated cross sections of heavy quarkonium production at high hadronic or photon-hadron collision energy is discussed. We resolve this problem via the…

Direct photon production in hadronic collisions provides a handle on the gluon PDF by means of the QCD Compton scattering process. In this work we revisit the impact of direct photon production on a global PDF analysis, motivated by the…

We study the cross section for the photoproduction reaction gamma N -> h X in fixed-target scattering at COMPASS, where the hadron h is produced at large transverse momentum. We investigate the role played by higher-order QCD corrections to…

Jet production at hadron colliders provides powerful constraints on the parton distribution functions (PDFs) of the proton, in particular on the gluon PDF. Jet production can also be used to extract the QCD coupling constant and to test its…

The complete details of our calculation of the NLO QCD corrections to heavy flavor photo- and hadroproduction with longitudinally polarized initial states are presented. The main motivation for investigating these processes is the…

Gluon PDFs, GPDs and TMDs play a significant role in an array of scattering processes, including SIDIS, DVCS, exclusive meson electroproduction and p - p scattering. Spin dependent gluon distributions can lead to distinctive features in the…

The first measurement of the top quark pair production cross section ($\sigma_{\rm{t}\bar{\rm{t}}}$) in proton-proton collisions at $\sqrt{s} = 5.02$ TeV is reviewed. The data have been collected by the CMS experiment at the LHC and…

We compare the single inclusive spectra of isolated photons measured at high transverse energy in proton-antiproton collisions at sqrt(s)=1.96 TeV with next-to-leading order perturbative QCD predictions with various parametrizations of the…

We present the first lattice QCD determination of the light cone gluon helicity correlation parton distribution function (PDF) with numerical evidence toward disfavoring negative gluon polarization in the nucleon. We present a solution for…

We calculate the cross section for the inclusive production of single hadrons with finite transverse momenta in deep-inelastic scattering at next-to-leading order (NLO), i.e. through O(alpha_s^2), in the parton model of QCD endowed with…

The associated production of direct photons and heavy quarks at the LHC is presented. Predictions for the nuclear modification factor to the cross-section at ALICE are shown. It is demonstrated that this process is a great probe of the…

In this paper we explore the use of results on forward particle production at the LHC to constrain nuclear Parton Density Functions (nPDFs). The case study here is based on a possible future measurement of forward photon production with the…

The parton distribution functions (PDFs) provide process-independent information about the quarks and gluons inside hadrons. Although the gluon PDF can be obtained from a global fit to experimental data, it is not constrained well in the…